The present invention relates to archival memory devices and more particularly to novel ion implanted memory media and methods for the storage of digital data therein.
Modern information-processing applications frequently require the ability to store large quantities of data, usually in a digital binary format. The storage media must be non-volatile, whereby data is stored without change in content over long periods of time. In many applications, such as Social Security accounting and technological information retrieval systems, the digital information is initially entered into the memory and maintained essentially in an unchanged state for the entire storage interval, once the authenticity and parity of the data written into the memory is confirmed. Consequently, such memories are usually referred to as "read-mostly" memories, i.e., data is initially written; almost never changed in content; and is relatively permanently maintained therein with long intervals between writing of additional data, with frequent read operations being enabled to repeatedly retrieve the same stored information.
These archival memories require extremely high data capacity, frequently exceeding one tera-bit (10.sup.12 bits) per memory device. Entry of such vast amounts of data require the memory to be capable of extremely high writing (input) speeds, while useful reading (output) of the stored information mandates that wide bandwidth be provided. Additionally, the output signal should possess exemplary signal-to-noise ratios (requiring high device gain), so as to produce the required read-data reproducibility.